Modeling of spin-filtering properties of the dangling zigzag octagraphene nanoribbon by saturated hydrogen atoms

Within the framework of the theory of the electron density functional and the method of nonequilibrium Green functions (LSDA + NEGF), transmission spectra, current-voltage characteristics and differential conductivity of a dangling octagraphene nanoribbon obtained by removing carbon atoms from the central part and saturated with hydrogen atoms were investigated. It was shown that the current-voltage characteristics of the nanostructures under consideration have a region with negative differential resistance due to resonant tunneling of quasiparticles. The same changes are observed on the dI/dV characteristic. It has been established that in the circumscribed octagraphene nanoribbon (the hexagonal elements of which are connected by a triatomic carbon bridge), the passage of quasiparticles with spin down is blocked in the energy range -1.65 ÷ -0.5 eV. This behavior of the transmission spectrum allows us to apply them to create spin energy filters. It was found that the spin-polarized current of a dangling octagraphene nanoribbon (the parts of which are interconnected by pentagonal elements and a carbon bridge) with a state of up-up spins significantly exceeds the current of the structure with a state of up-down spins. This effect allows the selection of quasiparticles with a spin-up current in a certain value of the applied voltage. The results obtained can be useful in the calculations of new spintronics devices.

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